Workshop Summary: Rickettsial Diseases at the Vector-Pathogen Interface Rickettsial diseases are significant causes of morbidity and mortality. They are responsible for the majority of hospital admissions, intensive care admissions, and fatalities among all tick-borne infections. Many are emerging or re-emerging, have biothreat implications, and/or are neglected. Rickettsial diseases have been responsible for the loss of millions of lives and were second only to malaria as the cause of febrile illness among troops in World War II, the Korean War, and the Vietnam Conflict. No vaccine for any rickettsial disease exists, and the interactions of these bacteria with their arthropod vectors are poorly defined, yet this is an important interface for the development of transmission intervention strategies. Filling knowledge gaps in this arena will improve understanding of rickettsial development and lead to research for novel treatments and interventions. Indeed, the 2011 National Academies of Medicine workshop report, ?Critical needs and gaps in understanding, prevention, amelioration, and resolution of Lyme and other tick-borne diseases? emphasized that understanding these pathogens? factors that enable them to survive and cause disease would lead to development of novel countermeasures. The complexity of the challenge of preventing rickettsial diseases is due, at least in part, to the evolutionary relationships between the etiologic agents and their arthropod vectors. The American Society for Rickettsiology (ASR) has a long history of providing forums that foster scientific interactions and rich intellectual exchange among world-renowned experts on rickettsial diseases. The 30th Meeting of the ASR will be held June 8-11, 2019 at the El Dorado Hotel and Spa in Santa Fe, New Mexico. Approximately 200 attendees representing junior and established scientists from academia, government, and industry are anticipated. The conference?s overarching goal is to advance knowledge and stimulate interactions among these researchers through lectures, short oral presentations, poster sessions, and networking opportunities. To address the aforementioned knowledge gap, we propose a short workshop within the framework of the 30th meeting entitled, ?Rickettsial Diseases at the Vector-Pathogen Interface.? The workshop?s aims are to (i) provide a forum that promotes scientific exchange among participants and experts through invited keynote and senior talks, short talks, and posters by leaders and junior investigators that study rickettsial and other vector-borne pathogens; (ii) offer a program that presents the latest, cutting-edge research on rickettsial and other diseases caused by arthropod-borne/obligate intracellular pathogens; (iii) provide a venue that fosters intellectual exchange and networking opportunities between junior and senior investigators; and (iv) promote participation by those that are early in their careers and that are underrepresented in the biomedical sciences, including women. Efforts will also be made to accommodate attendees in need of child care. Support for the workshop is requested to cover the cost of coordination, facilities, travel expenses for invited speakers and selected attendees, and for audio- visual services and program production.